have found irkngthand on map it says there is a door to irkngthand arcanex yet cant seem to find any door. anyone know anything about this place? (other than its a dwemmer ruin i do know that much)

The location is quest-locked. Without console commands the interior is only accessible when you are sent there in the main Thieves Guild questline.

IIRC the actual door to the interior is way up top of the exterior ruin, you have to follow the steps and wooden walkways and makeshift bridges put down by the bandits who are camped out there. You can either fight your way through from the front or jump down to the top portions of the ruin by coming down the mountainside behind it. But either way the door to the interior is locked tight unless you are there for the appropriate TG quest.